1. Field of the Invention
The present invention relates to a light receiving device and a method for manufacturing a light receiving device.
2. Description of the Related Art
A compound semiconductor light receiving element array is disclosed in International Publication No. WO 2011/089949. A Type-II InAs/GaSb super-lattice structure is disclosed in A. Gin et. al., “Ammonium sulfide passivation of Type-II InAs/GaSb superlattice photodiodes”, APPLIED PHYSICS LETTERS, VOLUME 84, NUMBER 12, pp. 2037-2039, 22 Mar., 2004.
A light receiving device including a light receiving layer composed of a III-V group compound semiconductor such as GaSb, containing antimony as a constituent element, exhibits sensitivity to, for example, light in a mid-infrared light region. The light receiving layer of the light receiving device has a super-lattice structure in which GaSb layers and InAs layers are alternately stacked, for example. This light receiving device (photodiode) is also utilized for an image sensor, for example. The image sensor includes a plurality of light receiving devices arranged in the shape of an array. This photodiode has, for example, a mesa structure. In order to form this mesa structure, an etching method such as a dry etching method or a wet etching method, is used. In production of the image sensor, a substrate product including a plurality of light receiving devices with the mesa structures is formed by this etching step. The plurality of mesa structures is device-isolated from each other by grooves in this etching step. After the etching step, a passivation film is formed on the mesa structure.